Dosing device for bulk goods

ABSTRACT

A dosing device for bulk goods comprises a mounting frame ( 2 ) in which a trough ( 4 ) with a dosing screw ( 28 ) is arranged, a drive motor ( 30 ) and at least one first vibrating paddle ( 48 ). The trough ( 4 ) comprises two opposing sidewalls ( 14, 16 ), of which at least one flexible sidewall ( 14 ) is flexible and the vibrating paddle ( 48 ) is arranged on said flexible sidewall ( 14 ). The upper edges of said sidewalls ( 14, 16 ) are not parallel to each other. A significant improvement in mass flow may be achieved, with a particularly effective prevention of cavity formation, whereby any bulk goods bridges which are formed are rapidly and effectively broken. Even bulk goods which have a clearly poor flow characteristic and tend to clump or stick to the trough sidewalls can be dosed without problems.

The present invention relates to a dosing device for bulk goods,comprising a mounting frame in which a trough with a dosing screw isarranged, further a drive motor and at least one first vibrating paddle,the trough having at least two opposing side walls, at least one ofthese side walls being flexible and the vibrating paddle being arrangedon said flexible side wall.

The dosing device is preferably configured as follows: the entire troughconsists of a flexible material and may be suspended in the mountingframe. The drive motor is arranged in the back region of the mountingframe. The vibrating paddles are arranged at the sides next to thesuspended trough.

Dosing devices of this type are known and are used in variousindustries, for example in chemical plant, pharmaceutical plant, foodplant, etc. In order to keep the bulk goods, for example powder,granules, pellets, flakes, chips, flocks, fibers and the likefree-flowing and to prevent sticking on the trough walls, arrangementsfor the periodic inward arching of predetermined wall regions areprovided at least on the side walls of the trough, which is square in aplan view and assist the natural flow characteristic of the bulk goodsby activating the bulk goods in order to prevent compaction, bridgingand sticking.

Brochure No. 1000 d/e/f LG 3, “Der Brabender-FlexWall®-Dosierer”,manufactured by Brabender Technologie KG, Kulturstraβe 55-73, D-47055Duisburg, discloses a dosing device of this type in which so-calledpaddles arranged on motor-driven oscillating shafts, strike the troughwalls from the exterior. Individual drive motors are provided in eachcase for the dosing screw on the one hand and the paddles on the otherhand. The fitting of two drive motors with their respective mechanicaland electrical installation make the dosing device complex and expensivein terms of construction and assembly and in terms of the space requiredand the overall weight of the device.

Despite the advantages of said dosing device, it still requiresimprovement with respect to the mass flow, prevention of cavityformation and bulk goods bridges in the trough, in particular in thecase of bulk goods having poor flow characteristics.

It is accordingly the object of the invention, with the dosing devicementioned at the outset, to achieve a further considerable improvementin the mass flow with particularly effective prevention of cavityformation in the trough, any bulk goods bridges which have alreadyformed being broken rapidly and effectively. Even bulk goods which havepoor flow characteristics and tend to clump and to stick on the troughwalls should be able to be dosed without difficulty.

This object is achieved according to the invention with the dosingdevice mentioned at the outset in that the upper edges of said sidewalls are not parallel to one another.

The problem of possible bulk goods bridges and cavity formation issolved particularly advantageously and effectively by the combination ofthe geometry according to the invention of the trough with paddlesacting on the corresponding side walls.

It is particularly advantageous if the side walls of the trough and thenon-parallel upper edges converge toward the bottom region in the formof a wedge and the dosing screw is arranged in this bottom region of thetrough.

Owing to this overall form of the trough (see also FIGS. 7 and 9), theangles of inclination of the side walls with the non-parallel upperedges differ in the direction from the front at the screw outlet to theback. Owing to this trough geometry, a bulk goods bridge or a cavitycannot be formed or can only be formed in an unstable manner. A bulkgoods bridge which is possibly still formed in the case of bulk goodshaving poor flow characteristics is destabilized and destroyed moreeffectively and rapidly by the movement of the paddles acting on theflexible side walls because the side walls which form the supports forthe bulk goods bridge, unlike in troughs with rectangular geometry,converge in a non-parallel manner (see also FIGS. 8 and 10).

Owing to the oblique position of the paddles, which extend parallel tothe respective flexible side wall, a dynamic transverse component actsin the direction of the dosing screw and, owing to the oblique positionof the side walls, a static transverse component additionally acts onthe bulk goods, the combination of the two transverse components beingparticularly effective in preventing or destroying bulk goods bridges.This applies, in particular, when two opposing paddles are arranged onthe trough and the paddles move in the same direction, not in oppositedirections. Movement of the paddles in opposite directions, in otherwords when the paddles move toward one another and then apart again isin fact generally undesirable as this mode of operation would lead tocompaction of the bulk goods located in the trough. This applies, inparticular, to bulk goods which have a tendency to the known and feared“snowball effect”, namely clumping and compaction, even when minimalpressure is exerted.

In a particularly advantageous embodiment of the invention it isprovided that the upper edges of the non-parallel side walls converge inthe direction of the outlet of the dosing screw. In fact, as theflexible side walls, which periodically arch to and fro, throw the bulkgoods backward to the wide end of the trough, the bulk goodspurposefully reach the part of the bottom region of the trough filled bythe screw flight. The bulk goods are discharged at the narrow end of thetrough at which the outlet is arranged. This embodiment results inparticularly advantageous synergistic cooperation of the features oftrough geometry and the arrangement of the outlet which leads to optimumemptying of residues from the dosing device.

In a further preferred embodiment of the invention, the trough has atrapezoidal shape in the plan view from above, the dosing screw beingarranged substantially at right angles to the parallel sides of thetrapezoid. The term “trapezoid” is interpreted in the conventionalmanner as a plane quadrilateral with two parallel sides of unequallengths.

It is advantageous if at least one respective vibrating paddle isarranged on each of said opposing side walls and both side walls areflexible. The bulk goods are therefore moved mechanically from bothsides of the dosing device.

If the desired dosing capacity is greater than that of a single dosingdevice, it is more expedient to arrange a plurality of standard dosingdevices in a circle round the discharge point than to have a singlecorrespondingly greater dosing device especially produced for onepurpose. This also simplifies maintenance and procurement of spareparts. It is particularly advantageous for achieving the most compactarrangement of the individual dosing devices in the circle if the angleenclosed by the non-parallel upper edges forms an integer fraction ofthe full circle and, in particular, is 60°.

For the same reasons, it is advantageous if an arrangement of aplurality of identical dosing devices arranged in a closed or opencircle round a central discharge point is provided.

It is further provided that the drive motor is pivotal between anoperating position coupled to the dosing screw and an uncoupled shutdownposition, wherein the vibrating paddle(s) may be driven with anoscillating shaft via an oscillating drive, wherein means are providedfor an oscillating drive connection between the drive motor of thedosing screw and the oscillating shaft of the vibrating paddle or thevibrating paddles.

The oscillating drive preferably drives an oscillating shaft, arrangedsubstantially parallel to a side wall of the trough, with the vibratingpaddle.

As a result, the dosing device is simpler in terms of construction andassembly, requires less space and has a lower overall weight than theabove-mentioned known dosing device, and the dosing screw and thebearing can easily and quickly be pulled out backwards for disassembly.

Preferably, the module consisting of the gear means and the drive motorof the dosing screw is arranged pivotally as a whole so the dosing screwand bearing can be pulled out backwards, i.e. counter to the conveyingdirection.

It has been found that, even when allowing for the design andconstructional complexity of this gear means—the overall complexity andtherefore the total cost of the dosing device according to the inventionis lower than that of a dosing device of the known type.

In a preferred construction solution it is provided that the gear meansbe associated with the pivotal drive motor and comprise connecting meansto maintain the driving connection from the gear means to the pivotshaft of the paddle even when the drive motor is pivoted into theshutdown position, without disassembling any parts, as shown in moredetail by means of an embodiment. According to a further embodiment, thegear means may also be associated with the mounting frame and be coupledthereto, for example when the drive motor pivots into the operatingposition thereof, in a similar manner to the dosing screw, or else mayform a continuous drive connection with a gear element in the powertrain of the dosing screw, as shown in a further embodiment.

In one construction solution of the invention, the means comprise acrank mechanism which is connected in terms of drive to the drive motorand is connected via a connecting rod to a crank arm arranged on theoscillating shaft. Crank mechanisms are components of very simple designwhich are widely used for converting rotational movements intooscillating movements.

For changing the amplitude of the paddles, it is further provided thatthe eccentricity of the drive motor-side and/or oscillating shaft-sidelink point of the connecting rod to the crank mechanism or crank arm isvariable. In this embodiment, the amplitude of the oscillating movementof the paddle increases, the greater the eccentricity of the respectivelink point.

In a preferred embodiment of the invention, the drive motor-side crankmechanism comprises a rotationally driven crank disc with one or morelink points, arranged eccentrically to the axis of rotation of the crankdisc, for the connecting rod. A solution of this type is extremelysimple and inexpensive in construction.

In a further embodiment of the invention, it is provided that the crankdisc is an output gear-wheel of gearing driven by the drive motor.Gearing of this type allows easy production of different reduction ortransmission ratios between the rotational frequency of the drive motorof the dosing screw and the striking frequency of the paddle.

For adapting this reduction or transmission ratio between screw speedand paddle frequency to different bulk goods, it is provided in afurther embodiment of the invention that the output gear-wheel (crankdisc) and/or a drive gear-wheel cooperating therewith of the gearing maybe exchanged in order to change the transmission, to create differentpairs of gears.

A particularly simple constructional solution is achieved if the crankdisc is a toothed belt disc connected in terms of drive to a drivegear-wheel which is arranged on the output shaft of the drive motor andis configured as a toothed belt disc, via a toothed belt. Toothed beltgears of this type have the advantage that they are substantiallymaintenance free and run with minimal noise.

With the previously mentioned solution with gear means associated withthe pivotal drive motor, it is provided that the drive-side crankmechanism is arranged on a carrier which carries the drive motor and ismounted pivotally about the pivot axis on the mounting frame and thatthe connecting rod is connected to the oscillating shaft-side crank armvia a hinged joint of which the hinge axis is at least substantiallyaligned with the pivot axis of the carrier in a predeterminedoscillating position of the crank arm. In the predetermined oscillatingposition of the crank arm, the hinge joint allows a pivoting movement ofthe connecting rod about the hinge axis when the carrier is pivotedabout the pivot axis aligned with the hinge axis. The above-describedsolution allows dosing devices without paddle mechanisms to be convertedin a particularly simple manner at a later stage.

To allow the oscillating movement of the connecting rod in the crankplane, the connecting rod is connected to the hinged joint via a furtherconnecting hinged joint with a joint axis at right angles to the hingeaxis and to the longitudinal axis of the connecting rod.

Dosing devices of the type mentioned at the outset generally havepaddles arranged on both sides of the trough; in such a case, it isfurther provided according to the invention that at least one furtherpaddle is arranged in the mounting frame on the side, remote from thefirst paddle, of a trough and that an oscillating shaft of the furtherpaddle is coupled to the oscillating shaft of the first paddle via agear mechanism.

With a trough which is trapezoidal in a plan view, the oscillation axesof the two paddles are not arranged in parallel but obliquely to oneanother so the movements take place in a non-linear manner andnecessitate a correspondingly complex construction of the coupling andthe transfer of force.

This gear mechanism preferably comprises one respective crank armarranged on each oscillating shaft, the crank arms being connected toone another via a connecting rod. It is therefore proposed that themeans for an oscillating drive connection between the drive motor andthe oscillating shaft are configured as a gear mechanism which comprisesa respective crank arm arranged on each oscillating shaft and in thatthe crank arms are connected to one another via a connecting rod.

A plurality of embodiments of the invention are described in more detailhereinafter and illustrated in the drawings, in which:

FIG. 1 is a schematic side view of a dosing device;

FIG. 2 is a plan view of a dosing device (shown without the trough 4)according to FIG. 1, with the drive motor in an operating position;

FIG. 3 is a reduced plan view (shown without the trough 4) substantiallyaccording to FIG. 2, in which the drive motor is pivoted into a shutdownposition;

FIG. 4 is a schematic view toward the back wall of the mounting frameshowing details of the gear means for the oscillating drive of thepaddles;

FIG. 5 is a view counter to the direction of the arrow 18 in FIG. 2showing details of the oscillating drive for a second paddle;

FIG. 6 is a side view substantially corresponding to FIG. 1 of a furtherembodiment of the dosing device;

FIG. 7 is a plan view of a trapezoidal trough according to theinvention;

FIG. 8 is a plan view of a rectangular trough according to the priorart;

FIG. 9 is a view corresponding to the arrow 200 in FIG. 7 into theinterior of the trough;

FIG. 10 is a view in the direction of the arrow 202 in FIG. 8, also intothe interior of the trough.

The dosing device shown in FIGS. 1 to 5 comprises a substantiallyhousing-like mounting frame 2 in the upper opening of which a trough 4may be suspended in such a way that the upper peripheral edges 6 of thetrough 4 overlap the upper peripheral edges 8 of the housing-likemounting frame 2.

The housing-like mounting frame 2 has a back wall 10 and a front wall 12which are vertical and parallel to one another, as well as two sidewalls 14, 16 which also extend vertically but converge in the directionof the arrow 18 so the mounting frame 2 is trapezoidal in a plan viewwith a central plane of symmetry 19. This type of form is preferablyselected if a plurality of dosing devices are to be arranged in a circleround a central discharge point.

The trough 4 has a substantially wedge-shaped configuration. It has aback wall 20 and a front wall 22 which each form different angles ofinclination with the vertical, as well as two side walls 24 (see alsoFIGS. 4 and 5) which, in the embodiment illustrated, are arrangedsymmetrically to a vertical longitudinal centre plane of the trough 4,which coincides with the plane of symmetry 19 of the mounting frame 2,and converge at the bottom so that they form a bottom channel 26. Theside walls 24 also converge from the back wall 20 to the front wall 22so as to match the trapezoidal form of the mounting frame.

In the bottom channel 26 there is arranged, in a manner also known perse, a dosing screw 28 which may be driven by a drive motor 30 arrangedin the back region of the mounting frame 2 via a drive shaft 32 whichmay be coupled to the dosing screw 28 and conveys the bulk goods locatedin the trough 4 outwardly via an outlet nozzle 34. When the trough 4 issuspended in the mounting frame 2, the outlet nozzle 34 is received in aleading bearing shoulder 36 of the trough 4; a trailing bearing shoulder38 of the trough 4 receives the leading portion of a bearing andcoupling arrangement 40 with a connecting shaft 42 and the bearingthereof. The connecting shaft 42 produces a driving connection betweenthe drive shaft 32 of the drive motor 30 and the dosing screw 28, asshown clearly in FIGS. 1 to 3.

The drive motor 30 is fastened to a carrier 44 which may be pivotedabout a vertical hinge axis 78 from the operating position shown in FIG.2 into the shutdown position shown in FIG. 3 by means of a hinge 46 onthe back wall 10 of the mounting frame 2. To enable the trough 4, forexample, to be removed from the mounting frame 2, the carrier 44 withthe drive motor 30 arranged thereon, may be pivoted into the shutdownposition shown in FIG. 3, the drive shaft 32 being uncoupled from theconnecting shaft, whereupon the bearing and coupling arrangement 40together with the dosing screw 28 coupled thereto may be removed at theback; the outlet nozzle 34 fastened on the front wall 12 by means of aflange 35 may also be released and removed at the front. The trough 4 istherefore released and may be lifted upwardly from the mounting frame 2.Insertion of a trough 4 into the mounting frame 2 similarly takes placein reverse sequence.

The trough 4 consists of a flexible plastics material, preferably of apolyurethane material, so that its walls may easily be deformed, i.e.arched inwardly. As shown in the figures, what are known as vibratingpaddles 48, 50, each arranged on associated oscillating shafts 52 and54, are provided in each case next to the trough 4 in the mounting frame2. The paddles 48, 50 perform torsional vibration movements, strikingthe side walls 24 of the trough 4 and loosening the bulk goods locatedin the trough. As shown in FIGS. 1 to 4, the respective oscillatingshafts 52, 54 are fastened by associated bearings, not described indetail, on the back wall 10 and the front wall 12 of the mounting frame2. The oscillating shaft 52 is extended outwardly beyond the back wall10 of the mounting device 2; a crank arm 56 by means of which atorsional vibration movement may be introduced into the oscillatingshaft 52 is arranged on the extension 52′.

The oscillating drive of the oscillating shaft 52 is derived from thedrive motor 30 of the dosing screw 28 via special gear means. These gearmeans comprise a crank mechanism 58 which is connected to the drivemotor 30 in terms of drive and is connected via a connecting rod 60 tothe crank arm 56. The crank mechanism 58 substantially consists of arotationally driven crank disc 62 with a link point 66 for theconnecting rod 60 arranged eccentrically to the axis of rotation 64 ofthe crank disc 62. The crank disc 62 is mounted via a crank disc shaft68 on the carrier 44 to which the drive motor 30 is also fastened. Thecrank disc 62 forms an output gear-wheel of a transmission which isdriven by the drive motor; a drive gear-wheel 70 is splined on the driveshaft 32 of the drive motor 30. The drive gear-wheel 70 and the crankdisc 62 are each configured as toothed belt discs which are connected interms of drive via a toothed belt 72.

As shown, in particular, in FIG. 3, the crank mechanism 58 is arrangedrigidly on the carrier 44 and, as the drive motor 30 is pivoted into itsshutdown position, the crank mechanism 58 is pivoted therewith. Toenable the drive connection from the crank mechanism 58 to the crank arm56 of the oscillating shaft 52 to be maintained even during thispivoting movement, the connecting rod 60 is connected to the crank arm56 via a hinge joint 74 of which the hinge axis 76 is at leastsubstantially aligned with the pivot axis 78 of the carrier 44 in apredetermined oscillating position of the crank arm 56 shown in FIG. 4.In this position, the distance between the link point 66 on the crankdisc 62 and the hinge axis 76 of the hinge joint 74 remains equal duringthe pivoting of the carrier 44 so the pivoting movement of the carrier44 is not obstructed. It has also be found that, if the crank arm 56does not adopt this predetermined oscillating position, pivoting of thecarrier 44 is still possible because the crank disc 62 and/or the crankarm 56 automatically run into a reciprocal position which does notobstruct the pivoting.

The connecting rod 60 is connected to the part of the hinge joint 74which is rotatable about the hinge axis 76 via a further connectingpivot joint 80 which allows the crank movement of the connecting rod 60owing to the rotation of the crank disc 62.

As shown, in particular, in FIGS. 2, 3 and 5, the oscillating shaft 52of the paddle 48 and the oscillating shaft 54 of the paddle 50 areconnected to one another in terms of drive via a gear mechanism 82arranged inside the mounting frame 2. This gear mechanism 82 comprises acrank arm 84 arranged on the oscillating shaft 52, a crank arm 86arranged on the oscillating shaft 54 and a connecting rod 88 connectingthe crank arms 84, 86. The two paddles 48 and 50 are accordingly eachdriven in the same direction.

To change the oscillating frequency of the paddles 48, 50, the drivegear-wheel 70 and/or the crank disc 62 may be exchanged so as to producedifferent transmission ratios between the rotational frequency of thedrive shaft 32 and therefore the dosing screw 28 on the one hand and theoscillating frequency of the oscillating shafts 52, 54 on the otherhand. It has been found that a ratio of 1:1 is advantageous in the caseof bulk goods having poor flow characteristics; the speed of the dosingscrew may be three times as high as the oscillating frequency of thepaddles in the case of bulk goods having very good flow characteristics.With a standard setting, where the rotational frequency of the dosingscrew is twice as high as the oscillating frequency of the paddles, awide range of diverse bulk goods is optimally covered.

In order to vary the oscillation amplitude of the paddles 48 and 50, thecrank disc 62 is provided with a plurality of link points 66, 88, 90, 92for linking the connecting rod 60, as indicated schematically in FIG. 4.

FIG. 6 shows a dosing device in a view corresponding to FIG. 1. Thedosing device in FIG. 6 differs from the dosing device in FIG. 1 only inthe arrangement and formation of the crank mechanism, so it is onlynecessary to describe the crank mechanism here. The crank mechanism 158,in turn, comprises a crank disc 162 formed as a toothed belt disc and adrive gear-wheel 170 also formed as a toothed belt disc: In contrast tothe arrangement according to FIG. 1, the crank disc 162 is mounted on alower portion of the back wall 110 of the mounting frame 102. The drivegear-wheel 170 is formed by a coupling bush 190 which is a component ofthe bearing and coupling arrangement 140 and is rotationally connectedto the connecting shaft 142. The crank disc 162 and the drive gear-wheel170 are in turn connected to one another by a toothed belt 172. As thecrank mechanism 158 is connected to the mounting frame 102, it remainsin place when the drive motor 130 pivots into its shutdown position. Ahinge joint corresponding to the hinge joint 74 can therefore bedispensed with, so the crank arm 160 is connected to the crank arm (notshown) of the oscillating shaft 152 merely via a connecting pivot jointcorresponding to the connecting pivot joint 80.

FIGS. 7 to 10 illustrate the advantages of the trapezoidal form of thetrough. The working space of the dosing screw 28 is designated byreference numeral 206 in FIGS. 9 and 10. The trapezoidal form of thetrough 4 (FIGS. 7 and 9) results in angles of inclination of the sidewalls 14, 16 which differ in the direction from the front at the screwoutlet to the back, as shown in particular in FIG. 9. Owing to thistrough geometry, a product bridge 204 which might be formed by powderhaving poor flow characteristics is destroyed more effectively by themovement of the paddles 48, 50 because the trough walls 14, 16 formingthe supports for the product bridge 204, in contrast to troughs withrectangular geometry (FIGS. 8 and 10), do not extend in parallel.

The movement of the flexible trough walls 14, 16 due to paddles or othercomponents produce, with the trapezoidal form according to FIG. 7, anoblique force component, shown by arrows in FIG. 7, on the productbridge 204. The transverse component contained therein destroys theproduct bridge 204 shown in FIGS. 7 and 9 particularly effectively. Incontrast, in troughs 4 with a rectangular cross-section in a plan viewand therefore side walls 14′, 16′ extending in parallel, it may happenthat the product bridge 204 is further compacted and consolidated by theaction of the paddles, as illustrated in FIGS. 8 and 10.

List of reference numerals  2 mounting frame  4 trough  6 upperperipheral edge of 4  8 upper peripheral edge of 2  10 back wall  12front wall  14, 14′ side wall  16, 16′ side wall  18 arrow  19 plane ofsymmetry  20 back wall  22 front wall  24 side wall  26 bottom channel 28 dosing screw  30 drive motor  32 drive shaft  34 outlet nozzle  35flange  36 bearing shoulder  38 bearing shoulder  40 bearing andcoupling arrangement  42 connecting shaft  44 carrier  46 hinge  48first vibrating paddle  50 vibrating paddle  52 oscillating shaft  54oscillating shaft  56 crank arm  58 crank mechanism  60 connecting rod 62 crank disc  64 axis of rotation  66 link point  68 crank disc shaft 70 drive gear-wheel  72 toothed belt  74 hinge joint  76 hinge axis  78pivot axis  80 connecting pivot joint  82 gear mechanism  84 crank arm 86 crank arm  88 link point 102 mounting frame 110 back wall 130 drivemotor 140 bearing and coupling arrangement 142 connecting shaft 152oscillating shaft 158 crank mechanism 160 connecting rod 162 crank disc170 drive gear-wheel 172 toothed belt 190 coupling bush 200 arrow 202arrow 204 product bridge 206 working chamber of dosing screw

1. A dosing device for bulk goods, comprising a mounting frame (2) inwhich a trough (4) with a dosing screw (28) is arranged, further a drivemotor (30) and at least one first vibrating paddle (48), the trough (4)having at least two opposing side walls (14, 16), at least one of theseside walls (14) being flexible and the vibrating paddle (48) beingarranged on said flexible side wall (14), wherein the upper edges ofsaid side walls (14, 16) are not parallel to one another and wherein theupper edges of the non-parallel side walls (14, 16) converge in thedirection of the outlet of the dosing screw (28).
 2. The dosing deviceas claimed in claim 1, wherein the side walls (14, 16) of the trough (4)and the non-parallel upper edges converge toward the bottom region inthe form of a wedge and wherein the dosing screw (28) is arranged inthis bottom region of the trough (4).
 3. The dosing device as claimed inclaim 1, wherein the trough (4) has a trapezoidal shape in the plan viewfrom above, the dosing screw (28) being arranged substantially at rightangles to the parallel sides of the trapezoid.
 4. The dosing device asclaimed in claim 1, wherein at least one respective vibrating paddle(48, 50) is arranged on each of said opposing side walls (14, 16) andboth side walls (14, 16) are flexible.
 5. The dosing device as claimedin claim 1, wherein the angle enclosed by the non-parallel upper edgesforms an integer fraction of the full circle and, in particular, is 60°.6. The dosing device as claimed in claim 1, wherein an arrangement of aplurality of identical dosing devices which are arranged in a closed oropen circle round a central discharge point is provided.
 7. The dosingdevice as claimed in claim 1, wherein the drive motor (30) is pivotalbetween an operating position coupled to the dosing screw (28) and anuncoupled shutdown position, wherein the vibrating paddle(s) (48, 50)can be driven with an oscillating shaft (52) via an oscillating drive,wherein means are provided for an oscillating drive connection betweenthe drive motor (30) of the dosing screw (28) and the oscillating shaft(52) of the vibrating paddle (48) or the vibrating paddles (48, 50). 8.The dosing device as claimed in claim 7, wherein the means comprise acrank mechanism (58) which is connected in terms of the drive to thedrive motor (30) and is connected via a connecting rod (60) to a crankarm (56) arranged on the oscillating shaft.
 9. The dosing device asclaimed in claim 8, wherein the eccentricity of the drive motor-sideand/or oscillating shaft-side link point (66; 138, 90, 92) of theconnecting rod (60) is variable.
 10. The dosing device as claimed inclaim 8, wherein the drive motor-side crank mechanism (58) comprises arotationally driven crank disc (62) with one or more link points (66;88, 90, 92), arranged eccentrically to the axis of rotation (64) of thecrank disc (62), for the connecting rod (60).
 11. The dosing device asclaimed in claim 10, wherein the crank disc (62) is an output gear-wheelof gearing driven by the drive motor (30).
 12. The dosing device asclaimed in claim 11, wherein the output gear-wheel or a drive gear-wheel(70) cooperating therewith of the gearing can be exchanged in order tochange the transmission.
 13. The dosing device as claimed in claim 11,wherein the crank disc (62) is a toothed belt disc connected in terms ofthe drive to a drive gear-wheel (70) which is arranged on the outputshaft (32) of the drive motor (30) and is configured as a toothed beltdisc, via a toothed belt (72).
 14. The dosing device as claimed in claim8, wherein the drive-side crank mechanism (58) is arranged on a carrier(44) which carries the drive motor (30) and is mounted pivotally aboutthe pivot axis (78) on the mounting frame (2) and wherein the connectingrod (60) is connected to the oscillating shaft-side crank arm (56) via ahinged joint (74) of which the hinge axis (76) is at least substantiallyaligned with the pivot axis (78) of the carrier (44) in a predeterminedoscillating position of the crank arm (56).
 15. The dosing device asclaimed in claim 14, wherein the connecting rod (60) is connected to thehinged joint (74) via a further connecting hinged joint (80) with ajoint axis at right angles to the hinge axis (76) and to thelongitudinal axis of the connecting rod (60).
 16. The dosing device asclaimed in claim 1, wherein at least one further paddle (50) is arrangedin the mounting frame (2) on the side, remote from the first paddle(48), of a trough (4) and wherein an oscillating shaft (54) of thefurther paddle (50) is coupled to an oscillating shaft (52) of the firstpaddle (48) via a gear mechanism (82).
 17. The dosing device as claimedin claim 7, wherein the means for an oscillating drive connectionbetween the drive motor (30) and the oscillating shaft (52) areconfigured as a gear mechanism (82) which comprises a respective crankarm (84, 86) arranged on each oscillating shaft (52, 54) and in that thecrank arms (84, 86) are connected to one another via a connecting rod(60).